In a virtualized computing environment, a virtual disk may be backed by a storage resource that includes multiple physical disks. Some of the physical disks may become heavily utilized, leaving other physical disks under-utilized. If a virtual disk becomes over-committed with respect to its storage space, the virtual disk may no longer be able to handle the additional storage space requests, as the heavily-utilized physical disks are exhausted of their physical storage capacity. Without a balanced storage resource, an over-commitment situation may greatly impact the overall performance of the virtual disk.